OPPO HA-2SE

Hybrid Class AB Amplifier

The HA-2SE's power amplification circuit for the headphones is Class AB built with integrated circuits (ICs) and discrete transistors. The discrete transistor output stage uses hand-picked and
matched parts. The output transistors are biased to operate in their most linear range for the critical small signal, and deliver their full potential when power is required.

Clean Signal Path

There is no DSP (Digital Signal Processor) in the HA-2SE. Volume control is operated by a combination of the DAC chip's internal digital volume control and an analog potentiometer (the familiar
volume knob). Bass boost is performed by pure analog audio circuits. By avoiding re-digitizing the audio signal for volume adjustment or bass boost, the HA-2SE provides a clean signal path for
the audio.

Audio-In and Line-Out

The HA-2SE has a 3.5 mm Audio-In port to support portable music players that do not have a USB-compatible digital output. While the HA-2SE is used with one of its USB digital input ports,
the 3.5 mm jack acts as Line-Out for the USB DAC.

ESS Sabre32 Reference DAC

The DAC is one of the most important components for digital audio playback. The ES9028-Q2M DAC chip used in the HA-2SE is the latest flagship mobile DAC developed by ESS Technology. With the ESS
patented 32-bit Hyperstream™ DAC architecture and Time Domain Jitter Eliminator, the SABRE32 Reference DAC delivers an unprecedented performance for mobile applications.

Asynchronous USB DAC

By bypassing the smartphone's built-in DAC and headphone amplification circuit that are often cost-constrained, the HA-2SE turns a smartphone into a high performance digital audio player. The
asynchronous USB DAC input of the HA-2SE also works with PC and Mac computers to replace the built-in sound card and support high-resolution audio playback with PCM up to 384 kHz 32-bit and DSD
up to 12 MHz (DSD256).

Bass Boost

For those who like a bit more punch and impact with their music, the HA-2SE offers a Bass Boost function. With Bass Boost off, the HA-2SE delivers a ruler-flat frequency response; with Bass Boost
on, the HA-2SE adds force and impact to the sub-bass region without muddling the important mid- to high-frequency bands.

Two Gain Settings

The HA-2SE offers two gain level settings for optimal headphone matching. The High Gain mode is capable of driving large power-hungry headphones, delivering up to 300 mW into 16-Ohm headphones.
The Low Gain mode is intended for sensitive In-Ear Monitor type earphones.